Automatically-locking sash balance



United States Patent 2,987,758 AUTOMATICALLY-LOCKING SASH BALANCE FredC. Osten, Sr., 14500 Abingdon Ave., Detroit, Mich. Filed June 10, 1959,Ser. No. 819,505

Claims. (Cl. 16197)' V This invention relates to sash balances and, inparticular, to automatically-locking sash balances for removable sashwindows.

One object of this invention is to provide an automatically-locking sashbalance for removable sash windows having a tilting locking member whichautomatically tilts into locking engagement with the sash balance casingupon removal of the sash, regardless of the state of tension of the sashbalancing spring or the location at which the sash is removed; andwherein reinsertion of the sash and ire-engagement with a portion of thesash balance automatically tilts the locking member into disengagementwith the sash balance casing so as to restore the application of thebalancing spring tension to the sash.

Another object is to provide an automatically-locking sash balance ofthe foregoing character wherein the sash balancing spring is connectedto the tilting locking member through a pivoting link which preventsbreakage at the connection between the sash balancing spring and thelocking member and also confines the tilting of the locking member tosubstantially a single plane so as to enhance its locking action as wellas to insure that its trig er portion properly engages the triggertripping device on the sash, thereby unlocking the sash balance andreapplying the tension of the sash balancing spring when the sash islowered to the location where the triggertripping device engages thetrigger portion of the locking member.

Another object is to provide an automatically-locking sash balance asset forth in the object immediately preceding, wherein the pivotingconnecting link between the sash balancing spring and the tiltinglocking member is inserted in a narrow-mouthed slot extending into thelocking member from at least one side thereof and preferablytherethrough so as to enable the lower end of the link to be inserted inthe locking member from one side or from either side, as the case maybe, thereby facilitating the assembly of the sash balance and reducingthe cost of production.

Other objects and advantages of the invention will become apparentduring the course of the following description of the accompanyingdrawings, wherein:

FIGURE 1 is an enlarged fragmentary vertical section through a portionof a window frame and an adjacent portion of a removable sash, togetherwith a sash balance equipped with a tilting locking member and pivotedlink connection to a sash balancing spring, and a tripping device in thesash frame, taken along the line 11 in FIGURE 3;

FIGURE 2 is a vertical longitudinal section taken along the line 2-2 inFIGURE 1, in a plane at right angles thereto;

FIGURE 3 is a horizontal cross-section taken along the line 33 in FIGURE1; and

FIGURE 4 is a view similar to FIGURE 1, but with the sash removed andthe sash balance automatically locked to the sash balance casing,according to the invention.

Referring to the drawing in detail, FIGURES l to 4 inclusive show inlongitudinal vertical section a portion of a removable sliding sashwindow installation, generally designated 10, as consisting generally ofa window frame 12 containing a sash guide 14 having a hollow rib orelongated sash balance casing 16 and an adjoining elongated flat orplate portion 18 in which the rib 16 is 1 ice located and with which, inthe form chosen for illustration of the invention, it is integral. Thesash guide 14, including the hollow rib 16, is conveniently made byextrusion of a suitable metal, such as aluminum or aluminum alloy, in amanner well-known to those skilled in the metal extrusion art.

Slidably engaging the sash guide 14 and grooved to receive the rib 16 is,a removable sliding sash, generally designated 20, shown onlyfragmentarily and containing the usual glass window pane (not shown).The vertical side rail 22 of the sash 20 has a guide groove 24 receivingthe outwardly-projecting portion 26 of the hollow rib 16, flanked by itsfront surface or edge 25. The inwardly-projecting portion 28 of thehollow rib 16 is seated in a groove 30 in the window frame 12. Thevertical side rail 22 of the removable sliding sash 20 contains a recess32 extending inwardly from the guide groove 24, which recess in turncontains a sash balance trigger-tripping device, generally designated 34(FIG- URES 1 and 3). Y

The trigger-tripping device 34 has a substantially tubular casing 36with a face plate or mounting plate 38 drilled to receive fasteners 40by which the trigger-tripping device 34 is held in position. The casing36 is of rectangular cross-section (FIGURE 3) with opposite parallelside walls 42 drilled in alignment to receive a pivot pin '44, the frontwall 46 having an elongated slot 48 therein. Pivotally mounted upon thepivot pin 44 is a swinging dog or catch 50 in the form of an arm havingan angled pointed tip 52 projecting through the slot 48. The catch 50 isinclined downwardly in its casing 36 through the opening 48 and theangled tip 52 has its lower surface inclined relatively to the straightupper surface of the arm 50 (FIGURE 1). its rearward surface is providedwith a socket 54in which is mounted the outer end of a compressionspring 56, the rearward end of which engages the rearward wall 58 of thecasing 36 as an abutment. By this means, the pointed tip 52 of the catch50 is constantly urged outwardly through the slot 48 but is adapted toyield inwardly by overcoming the force of the spring 56 so as r to swinginto the chamber within the casing 36 under the circumstances explainedbelow in connection with the operation of the invention.

The hollow guide rib or sash balance casing 16 is, as stated above, ofrectangular cross-section (FIGURE 3) located in the approximatemid-portion of the plate 18, and has a rear wall 60 within the groove 30of the window frame 12. The hollow rib 16 in the approximate center ofits forwardly-projecting portion 26 is provided with a front wall 62running from end to end of the rib 16, which contains an elongatedchamber 64. The front wall 62 is provided with a slot 66 likewiserunning from end to end of the wall 62 and extending into the chamber 64of the hollow guide rib 16.

The hollow guide rib 16 forms the elongated tubular casing of a sashbalance, generally designated 70, housed therein. The sash balance 70operatively coacts with the trigger-tripping device 34 in a mannerexplained below in connection with the operation of the invention.Hooked over the upper end 72 of the hollow guide rib or sash balance 16is the spirally-wound end portion 74 of the loop or eye 76 at the upperend of an elongated helical tension sash balancing spring 78', the loopor eye 80 at the lower end of which pivotally receives the hook loop 82on the upper end of a connection link 84. The latter at its lower endhas a cylindrical connection loop or male pivot bearing portion 86. Thelower loop 86 is seated in the approximately cylindrical bearing boreportion or second pivot element 88 of a keyhole slot 90 in the upperedge of a tilting locking member, generally designated 92. The upperportion or entrance passageway 94 of the key- The catch 50 in hole slot90 diverges upwardly from its junction 96 with the cylindrical bearingbore portion 88 so as to provide a narrowed entrance therebetween(FIGURE 1). The latter prevents escape of the cylindrical bearing loopSG from the-cylindrical bearing bore portion 88 of the keyhole slot 99whilepermitting rocking of the tilting rocking member or plate 92 as aresult of the converging or flared upper portion 94 of the keyhole slot90.

The tilting sash-locking plate 92 at its rearward upper corner isprovided with a sharp transverse locking edge locking plate 92 'at alocation below the sharp locking edge a 98 is bored transversely. toreceive a pivot pin or first pivot: member ltio upon which the lockingplate 92 is tiltably mounted" (FIGURES 1 and 4). The locking plate 92 istiltablyrnounted in a parallel-walled notch 108 in the upper end ofareciprocable guide block or lock carrier 110 reciprocably mounted inthe chamber 64 within the hollow guide rib or sash guide casing 16. Theopposite ends of the pivot pin 106 are. seated in aligned bores 112(FIGURE 2) inthe reciprocable guide block 110 on opposite sides of thenotch 108 in such a manner that the trigger portion 100' of thesash-locking plate 92 projects outward through the slot 66 of the guiderib 16 into the path of the pointed angled tip 5-2 of the catch 50 whenthe sharp locking edge 98 of the sashlocking plate 92 is in lookingengagement with the rearward wall 6% of the casing or guide rib 16.

As will be seen from FIGURES 1 and 4, themounting of the pivot pin 106slightly below and to the rear of the cylindrical portion 88 of thekeyhole slot 90 provides a locking lever arm for the locking plate 92having a length equal to the distance between the axis of the pivot pin106 and a vertical line dropped from the center of the cylindricalportion 88. The locking plate 98 is preferably of sintered powderedmetal. such as carbonized sintercd powdered iron for convenience ofmanufacture, thereby providing, in eifect, .a steel locking plate 92.The reciprocable block 110, on the other hand, is preferably made of atough material such as the polymeric amide synthetic plastic knowncommercially as nylon. The notch 108 in the front upper portion of theguide block 110 communicates with a slot 114 extending through theremainder of the block 110 to the rear thereof (FIGURE 4) Below thenotch 108, the guide block110 has a bottom wall or lower bridge portion116 with an approximately flat top surface 118 which acts as a stop whenengaged by the bottom edge 129 of the locking plate 92 (FIGURE 1) whenthe locking plate 92 is in turn engaged by the angled tip 52 of thecatch 50 with the sash in position within the window frame 12. Thelatter is recessed at 122 (FIG- URE'3) to receive a flange 124 of thefront plate 18 of the sash guide 14.

In the operation of the invention, let it be assumed that the removablesliding sash 2 0 has been inserted in the window frame 12 with its guidegroove 24 embracing the forward portion 26 of the hollow guide rib 16and with the catch 50.of the trigger-tripping device 34 engaging theabutmentsurface 162 of the trigger portion 190 of the locking plate 92(FIGURE 1). This condition occurs when the sash 29 has. been reinsertedin the window frame 12 at a location wherein the catch 50 is above thelocking plate 92 and wherein the sash 20' has been pulled downward tocause the lower side of the pointed tip 52 of the catch 59 to engage andtilt the locking plate 92 around its pivot pin 1116. so as to disengage.its sharp looking. edge 98 from locking engagement with the. rearwall-60- of the hollow rib .16.. The parts are now in the relativepositions shown in FIGURE 1, with the locking plate 92 in its unlockedposition and with the sash balancing spring 78 applying its balancingforce to the sash 20 through the trigger-tripping device 34. The catch50 is limited in its outer swinging by engagement with the upper end ofthe slot 48 from projecting through the slot 66 in the guide rib 16 toofar into the interior of the latter.

Let it now be assumed that the operator has removed the sash 20 bypushing it to the left against the springmounted opposing sash guide(not shown) (FIGURES l and 3) so' as to enable the front surfaces of thesash rail 22 to be brought out to the plane of the front wall 62 of thehollow guide rib 16, whereupon the sash 29 is swung outward or'inwardrelatively to the window frame 62 so that the front edge 25 passes overand beyond the guide rib portion 26,'so that it can then be removed.Such a spring-mounted opposing sash guide is disclosed in my co-pendingapplication Serial No. 611,509, filed September 2.4, 1956, now PatentNo. 2,903,736, dated September 15, 1959, for Automatically-Locking SashBalance for Removable Sash Windows, upon which the present invention isan improvement. The instant the sash 20 is pushed to the left,disengaging its pointed tip from the upper abutment edge 1tl2 ofthetrigger'portion 109 of the locking plate 92,. the balancing spring 78through its connecting link 84 with the locking plate 92, jerks thelatter upward in a clockwise direction around 9 its pivot pin 1% byreason of the lever arm provided between the pivot pin 106 and thecylindrical bearing groove 83 containing the lower cylindrical loop 86of the link 84. This action (FIGURE 4) causes the sharp locking edge orprong 98 on the rearward upper corner of the locking plate 92 to diginto the relatively softer metal of the back wall of the hollow guiderib 16 and consequently maintaining the balancing spring 78 in itstensioned condition.

When the sash 24) is reinserted in the window frame 12 by reversing theforegoing procedure, with the catch 50 of the trigger-tripping device 34above the location occupied by the guide block 108 andlocking plate 92,the sliding downward of the sash 21 causes the pointed tip 52 to engageand push downward upon the abutment surface 102 of the trigger portion160 of the locking plate 92 (FIGURE 1), tilting the locking plate 92 ina counterclockwise direction around its pivot pin 106 in the guide block198. This action disengages the locking prong or sharp edge 98 fromlooking engagement with the rear wall 66 of the hollow guide rib 16(FIGURE 1) and thus reapplies the tension of the balancing spring 28 tothe sash 20 through the trigger-tripping device 34.

If, on the other hand, the sash 29 is re-inserted in the window frame 12at a lower location wherein the triggertripping device 34 is below thelocked position of the locking plate 92, raising of the sash 20 causesthe arcuate forward edge 164 of the locking plate 92 to be engaged bythe upper side of the pointed tip 52 of the catch 50, pushing thelatter'inward into its casing 36 and compressing the spring 56. Thecontinued raising of the sash 20 causes the catch 50 to move outwardover the abutment surface 162 the instant the pointed end 52 passes thetrigger portion 190. Pulling downward upon the sash 21 thenengages thelower edge of the catch tip- 52 with the abutment surface 102 of thetrigger portion of the locking plate 92, tilting the latter about itspivot pin. 1G6 and disengaging its sharp edge or locking prong 98 fromlocking engagement with the rear wall 60 of the hollow guide rib 16.This action, as before, immediately re-applies the force of thebalancing spring 78 to the sash 20 through the link 8 locking plate 92and catch 50. t

The construction of the present invention employing the connecting link84 having its pivotal engagement with the locking plate 92 in a slot ofapproximately circular cross-section results in a much strongerconstruction than the flexible cable connection shown in myabovementioned co-pending application Serial No. 611,509, filedSeptember 24, 1956, in that it reduces the cable breakage occasionallyoccurring in the flexible cable used in my above-mentioned co-pendingapplication for connecting the balancing spring to the tilting lockingmemher. The present invention, by employing the freely pivotingconnecting link 84 avoids the breakage both of the cable clamp and ofthe cable itself and its connection to the tilting locking member, andalso provides a more eflicient pivot action since no flexing action of acable is involved in the pivot action. The provision of thelinkconnected tilting locking member of the present invention alsoreduces the cost of production by eliminating the prior operations ofbending the connecting cable, applying clamps thereto, threading it intothe locking plate and enlarging the lower end to fix it in position. Thepresent invention thus not only reduces the labor cost by eliminating anumber of previously-required operations but also obtains uniformity inthe quality of assembly of the sash balance.

What I claim is:

1. An automatically-locking sash balance for a remov able sliding sashwindow installation, said balance comprising an elongated hollow casinghaving an elongated aperture therein, a resilient sash balancing memberanchored to said casing and disposed therein, a lock carrierreciprocably mounted in said casing and having a first pivot elementthereon, a sash balance locking member tiltably mounted on said firstpivot element, said locking member having a second pivot element thereondisposed at a location spaced laterally away from said first pivotelement and providing a tilting lever arm therebetween, said lockingmember also having a trigger portion disposed adjacent said aperture inthe path of the sash and tiltable unitarily with said locking member anda locking portion disposed remote from said trigger portion and alsotiltable unitarily with said locking member into and out of lockingengagement with said casing in response to tilting of said lockingmember relatively to said lock carrier, and a connection link secured atone end to said resilient member and having at its opposite end ahearing portion thereon pivotally engaging said second pivot element ofsaid locking member in relatively turning relationship therewith, saidresilient member being responsive to the removal of the sash fromengagement with said trigger portion for pulling on said connection linkand thereby eifecting tilting of said locking portion around said firstpivot element into locking engagement with said casing.

2. An automatically-locking sash balance, according to claim 1, whereinsaid connection link comprises an elongated member having at one end afirst loop connected to said resilient member and at its opposite end asecond loop pivotally engaging said second pivot element of said lockingmember, said second loop forming said bearing portion of said link.

3. An automatically-locking sash balance, according to claim 1, whereinsaid second pivot element includes a bearing recess in said lockingmember and wherein said bearing portion of said connection link isdisposed in and rockingly engages said bearing recess.

4. An automatically-locking sash balance, according to claim 3, whereinsaid bearing recess includes a bearing bore and an entrance passageextending from one edge of said locking member to said bearing bore,said link passing through said entrance passageway.

5. An automatically-locking sash balance, according to claim 4, whereinthe opposite sides of said entrance passage diverge from said bearingbore toward said edge of said locking member, whereby to provideclearance for free relative tilting motion between said locking memberand said link.

References Cited in the file of this patent UNITED STATES PATENTS2,903,736 Osten Sept. 15, 1959

